Until the mid-18th century, the design and significance of maritime flags flying on ships in Tunis were unknown. However, various sources have been able to distinguish certain similarities among the flags: they were designed with a crescent-oriented shape in the presence of the colors blue, green, red, and white.[2] Thereafter, and until the early 19th century, the flag was composed of horizontal blue, red and green stripes, identifying the Ottoman regency in Tunis. This kind of flag with multiple bands and irregular contours floated on top of ships all along the coast of North Africa; similar flags with different colors and arrangements were also used on the[which?] continent.[2]

According to Ottfried Neubecker,[3] the bey of Tunis also had his own flag. This flag was most likely a simple personal banner of the ruler,[4] as it floated above the Bardo Palace, the Citadel of Tunis, on navy ships, and also in the center of the coat of arms in Tunisia. It was used at a number of public ceremonies—including at the proclamation of the Ottoman constitution on 21 March 1840[5]—until the abolition of the Bey monarchy on 25 July 1957.[3][6]

Believed to have been introduced by Al-Husayn II ibn Mahmud, although some sources, such as Abdel-Wahab, claim that it was in use three centuries earlier,[4] the flag was rectangular in shape and divided into nine stripes, the middle one green and double the size of all other bands, while the others alternated between yellow and red.[3] Featured in the center of the green stripe was the Zulfiqar, the legendary Islamic sword of Ali, with the blade in white and the hilt multicolored. The red and yellow stripes each contained five equidistant symbols, whose order was alternated between each stripe. These symbols were divided into two categories: one red six-sided star voided with a circle of a different color in the center—either a red star and green circle or a white star and blue circle—, and a large circle voided in its lower right by a small circle of different color, with the combination being either a small red circle within a larger blue circle or a small yellow circle within a larger red circle.[3] The first yellow stripe contains three red stars and two blue circles. The second stripe, red in color, contains three green circles and two white stars. The third stripe (second yellow one) is identical to the first, with the exception that the star in its center is white, while the fourth stripe (second white one) is identical to the second stripe.[3]

The naval ensign of the Tunisian navy from the 1830s, and national flag of Tunisia from 1959 to 1999, with a slightly thinner crescent than in the current design.

Several Muslim countries along the south coast of the Mediterranean Sea used a red flag similar to the flag of the Ottoman Empire.[7][8] After the destruction of the Tunisian naval division at the Battle of Navarino on 20 October 1827,[9] the sovereign Husainid Dynasty leader Al-Husayn II ibn Mahmud decided to create a flag to use for the fleet of Tunisia, to distinguish it from other fleets. There are some discrepancies over the date of the flag's adoption, as the government states that it was adopted in 1831,[10] while other sources like Siobhan Ryan's Ultimate Pocket Flags of the World claim that it was adopted in 1835.[11][12]

The flag that was used by some military units based in Tunisia while under French colonization.

During the era of the French protectorate in Tunisia, French authorities did not change the Tunisian flag.[dubious– discuss][13] However, according to an article in the Flag Bulletin publishing in Fall 2000, for a short period of time during the French protectorate, the flag of France was placed in the canton (upper left) of the Tunisian flag. In the same vein, vexillologistWhitney Smith stated that the addition of the French flag was "modification of the unofficial Tunisian national flag, used for a few years".[14][15] He added:

Tunisia, a French protectorate, retained its national flag on land and at sea. Nevertheless, in the late 19th Century or early 20th Century an unofficial version of the flag was used with the tricolor canton. In 1925 a formal proposal was made to adopt that flag as official, but no action was taken. That flag, featured on the cover of this issue [of the Flag Bulletin], does not appear to have been illustrated in any vexillological source.[16]

Confusion arose when an issue of the French daily newspaper Le Petit Journal, published on 24 July 1904 on the occasion of the bey of Tunis's visit to France, reproduced an illustration showing the flag used while was visiting the Hôtel de Ville, Paris.[17] Ivan Sache of Flags of the World claimed that this flag design, which hadn't been seen earlier, may have been inaccurate, suggesting that the journalist might not have been at the affair or he had reproduced a drawing of the wrong flag.[18]

The Tunisian flag was defined in Article 4 of the 1 June 1959 constitution under these terms: "The flag of the Republic of Tunisia is red, it has, under the conditions defined by law, in the middle, a white circle containing a five-pointed star surrounded by a red crescent."[19]

The Organic Law No. 99-56 of 30 June 1999,[20] adopted on 3 July[21] by the Chamber of Deputies, formalized the Tunisian flag for the first time in law, clarifying Article 4 of the constitution.[22] The flag is in the form of a red rectangle with a width equal to two-thirds of its length.[22] In the middle of the flag is a white circle whose diameter is equal to one-third of the length of the rectangle and whose center is located at the intersection of the diagonals of the rectangle.[22] A red five-pointed star is located to the right of the circle, whose center is at a distance equal to one-thirtieth of the length of the flag from the center of the circle.[22]

Construction diagram of the flag according to the 1999 law.

The location of the star's five points is determined by an imaginary circle centered around the star's center, its diameter equal to roughly 15% the length of the flag. The points of the star are equidistant from each other, and one of the points is located on the horizontal median of the flag to the left of the center of the imaginary circle. The star is surrounded on its left by a red crescent made by the intersection of two arcs, an outer arc whose diameter is equal to one-fourth of the length of the flag, and an internal arc with a diameter equal to one-fifth of the flag's length.[22] In addition, at the top of the flag used by the President of the Republic, the words "for the nation" (Arabic: للوطن‎) are written in gold.[22][23] The three outer edges of the flag are lined with golden yellow fringe and a red ribbon, with golden fringe on the right vertical side and a white disk with a star and crescent near the fringe, is attached to the flag pole above the flag.[22]

Article 4 of the 1959 constitution specifies the presence of a technical dossier containing a model of the flag, a guide to drawing it, which includes the proper measurements, and technical specifications of its colors.[22]

For the Tunisian embassy in France, the color red represents the blood of martyrs killed during the Turkish conquest of Tunisia in 1574.[13][24] However,[25] the Tunisians invited the Turkish to liberate them from the Spanish invaders and from what is left of the Hafside dynasty. Another interpretation is that the "red Beylical flag spread light throughout the Muslim world".[26] The white symbolizes peace, while the crescent and five-pointed star represent unity of all Muslims and the Five Pillars of Islam, respectively.[24]

According to Ludvík Mucha, author of Webster's Concise Encyclopedia of Flags & Coats of Arms, the white circle located in the center of the flag represents the sun. The red crescent and the five-pointed star, two ancient symbols of Islam, were most notably used on Ottoman flag and have since appeared on many flags of Islamic countries. The crescent is, from the viewpoint of an Arabic observer, supposed to bring good luck. The color red is a symbol of resistance against Turkish supremacy.[27] Whitney Smith states that the crescent was first emblazoned on standards and buildings in the Punic state of Carthage, located in present-day Tunisia. Since appearing on the Ottoman flag, they were widely adopted by Muslim countries, and have become known as symbols of Islam, when in fact, they may be cultural symbols.[28]

The Tunisian flag is visible on all public and military buildings. The flag also floats on the seats of Tunisian ambassadors at regional and international meetings as well as at buildings housing Tunisian representatives around the world.[24] It is deployed during commemorations and national honors in a strictly ceremonial manner.[24] On the listed Flag Days below, the Tunisian flag is flown in public buildings, compulsory by law:

The colors of the flag are included in other Tunisian symbols, such as the coat of arms, which contains a crescent and star enclosed in a circle with red border. In addition, equipment belonging to the Tunisian army are visually recognized by the presence of a cockade.

^Whitney Smith, The Flag Bulletin, no. 195, Sep.-Oct. 2000, pp. 171-194. "Another flag (Fig. 15), possibly introduced by Bey Hussein II, served on many occasions -- including the proclamation of the new Ottoman constitution on 21 March 1840. Referred to as the "state standard of the Regency," [footnote: Henri Hugon, "Les Emblèmes des beys de Tunis" (Paris: Leroux, 1913), p. 64] this flag was more than simply a personal banner of the ruler, although it appeared at ceremonies and visits in which the bey participated [footnote: Si Hassen Hosni Abdel-Wahab, "Note on the History of the Tunisian Flag" (Tunis, 1957), p. 3. The author claimed the standard was already three centuries old]). It was regularly used on the Bardo Palace, on the Citadel of Tunis, and on navy ships [footnote: Ibid and the captions of "Verzameling der Vlaggen by alle natien in gebruik" (Amsterdam, 1835-1850), a manuscript in the library of the Flag Research Center, illustration No. 37.]. ... The design of the standard [footnote: The flag --perhaps an elaborated version of the 1765 standard (...)-- as it appears in [smi75], p. 55, is an illustration from 1835 reproduced from the Verzameling.] varied somewhat over the years, but the basic elements were constant. (...) A simplified version of the standard (four stripes alternately green and red with sword of Ali overall in white) appeared on the white oval shield in the arms of the Regency, officially adopted in 1861 but in use earlier (Fig. 16) -- a rare example of a flag serving as the principal charge in the coat of arms of a country." (pp.185-186).